It is often necessary for business persons, doctors, dentists, service persons and others to maintain a personal appointments or schedule calendar on a daily or weekly basis in order to properly respond to a schedule of such appointments and events. In some instances, such time scheduling is performed by a secretary, dispatcher or other assistant; but most frequently, the person employs a hand written diary or calendar or schedule listing by dates of the various times of the appointments and events for future days or weeks. Periodic reference to such diary for each succeeding day reveals the appointments for that day. However, should the user neglect to consult his written diary, an important event or appointment may be overlooked and forgotten.
Similarly in many businesses there is a need for scheduling the time of crews or teams of persons to properly service the needs of customer. These schedules are often handwritten, and are updated or corrected by radio or telephone instructions.